1. Field of the Invention
This invention relates to water soluble corrosion inhibitor solutions. The invention also relates to a process for protecting metal from corrosion, particularly in the harsh aqueous and H.sub.2 S environment found in subterranean wells such as during petroleum production. More particularly, the invention relates to water soluble corrosion inhibitor compositions formed by reacting an amine mixture with an acid mixture (including petroleum wax oxidate) to form amides.
2. Prior Art
It is well known in the art to protect metal surfaces in subterranean well bores with corrosion inhibitors which include carboxylic acids and ammonia compounds. U.S. Pat. Nos. 3,712,862 and 3,712,863, Bundrant et al., describe the reaction of monomeric acids with petroleum wax oxidate to form either an amide or an imidazoline which is not water soluble (less than 250 ppm), but is oil soluble or dispersible. These inhibitors fall through the oil layer in the well bore and into the aqueous phase at the bottom of the well. A weighting agent is released and the inhibitor rises to the oil-water interface. Because of the nature of the inhibitor fluid, batch treatment is administered which requires the well be shut in for 24 to 48 hours to allow the inhibitor to separate from the weighting material. Solutions of the present invention have different properties from those of Bundrant et al. One manifestation of this difference is the difference in application for corrosion inhibition as is described herein.